Modifying Default Permissions with umask

When you, as a regular user, create a file, it's given a set of default permissions of 664, while directories get 775. For the mighty root user, file permissions default to 644 and directories to 755. These defaults are influenced by the umask value. You can check your default umask value by typing umask like this:

umask

Default permission configuration example

If you ignore the leading zero for the moment, your umask value is essentially a mask that hides what would otherwise be completely open permissions for a file (666) or a directory (777). A umask value of 002 means that directory permissions become 775, and file permissions become 644, assuming execute permissions are disabled by default for regular files as standard.

You can alter your umask value temporarily by using the umask command. Afterward, you can create files and directories to observe how the umask value influences permission settings.

Here are some examples:

Examples of different umask values

If you want to change your umask value permanently, add a umask command to the .bashrc file in your home directory.